Circulatory System

Heart

the pump that imparts pressure to the blood to stablish the pressure gradient needed for blood to flow to the tissue

Blood vessels

the passageways through which blood is directed and distributed from the heart to all parts of the body and subsequently returned to the heart

Blood

transport medium

Hematocrite

the percentage of red blood cell volume to total blood volume in a centrifuged blood sample

The constant movement of blood

keeps the cellular elements rather evenly dispered within the plasma

Blood plasma

a complex liquid in which the cellular elements 55% of blood volume

Plasma consists of

90% water, 1% inorganic constituent (ions), 6-8% organic (plasma proteins), small percentage of organic substance are nutrients, watse, dissolved gasses and hormones

Albumins

found in the liver, is 60% of the total percentage, helps maintain colloid osmotic pressure

Globulins

found in the liver, is 30% of the total percentage, help maintain colloid osmotic pressure

Fibrinogen

found in the liver, is 4% of the total percentage, plays a key role in blood coagulation

Function of Plasma

1. Transports vital substances such as nutrients, gases ,waste and vitamins

2. Maintains stability of interstitial fluid

3. Distributes Heat

4. Maintaion pH

Erythrocyete

Red Blood Cells

RBC counts

the number of RBCs in a cubic millimeter of blood

RBC counts reflects

blood oxygen carrying capacity

Anatomic features of erythrocytes

1. Flat, disc-shaped cells indented in the middle on both side

2. Flexible membranes

3. they carry he

Disc-shaped cells indented in the middle on both sides

a larger surface area for diffusion of O2 from the plasma across the membrane

Flexible Membrane

deform as they squeeze single file through capillaries as narrow without rupturing

lacking organelles

to maximize its hemoglobin content

Hemo(globin)

a protien made up of four highly folded polypeptide chains

(Hemo)globin

four iron bonded with oxygen in a reversible reaction

destruction of RBCs occure

every 120 Days

Where does destruction of RBCs take place

the liver, spleen, and red bone marrow

what facilitates the destruction of RBCs

large white blood cells (macrophages)

The iron from the heme group will be stored in the

liver

The iron from the heme group will be stored as

ferritin

RBCs destruction

1. the heme molecules will be metabolized and biliverdin, a greenish pigment, will be released.

2. Biliveredin will then get convereted to bilirulain, will eneter the liver, then released into the digestive systems

3. The goblin molecules, broken down into amino, can be used to synthesis new proteins.

Leukocytes

White blood cells (WBC)

Leukocytes are classified according to

the appearance of their nuclei and the presence or absence of granules in their cytoplasm

Granular leukocyte /polymorphonuclear

1. Neutrophlis

2. Eosinophils

3. Basophils

Granulocytes

“granule-containing cells”. their nuclei are segmented into several lobes of varying shapes, and their cytoplasm contains an abundance of membrane- enclosed granules

Agranular leukocyte / mononuclear

1. Monocyte

2. Lymphocytes

Agranulocytes

“Cells lacking granules”. Both have a single, large, non-segmented nucleus and few granules

Neutrophils

1. 50%-70% of leukocytes

2. multi-lobed nucleus

3. light purple granules (neutral stain)

4. specialized in phagocytosis

5. first responders

6. elevated in bacterial infection

Eosinophils

1. 1%-3% of leukocytes

2. Bi-lobed nucleus

3. Deep red granules

4. Moderate allergic reaction

5. Elevated in parastic worm infections and allergic conditions

6. secretes enzyme that dissolve clots

Basophile

1. less than 1% of leukocytes

2. Nucleus lobed; cytoplasmic granules stained blue in hematoxylin stain

3. Similar structurally and functionally to mast cells

4. Synthesize and store histamine and heparin

Monocytes

1. 3% - 9% of leukocytes

2. Spherical, kidney-shaped, nuclei

3. May leave bloodstreams to become macrophages

4. Phagocytize bacteria, dead cells and other debris

Lymphocytes

1. 25%-33% of leukocytes

2. large spherical nucleus surrounded by thin rim of cytoplasm

3. lymphocytes provides immune defense

4. B lymphocytes: produce antibodies ( humoral immunity )

5. T lymphocytes (cell-mediated immunity) : directly destroy their specific target cells by releasing chemicals that punch holes in the victim cell

WBCs functions

1. defend against invading disease-producing by microorganisms

2. functions as cleanup crew that removes wornout cells and tissue debris

3. identifies and destroys cancer cells that arise in the body

blood platelets (thrombocytes)

cell fragments of megakaryocytes that lack a nucleus and are roughly half the size of RBC .

there is approximately 250/ml of blood

functions of blood platelets

help repair damaged blood vessel by sticking to broken surface

Hemostasis

stoppage of blood

action that limit or prevent blood loss

1. blood vessel spasm

2. formation of a platelet plug

3. blood coagulation

what happens when platelets are broken down

releases thromboplastin in the plasma which turns into prothrombin that then turns to thrombin which will release fibrinogene which will turn to fibrin

Where are RBCs produced in the fetus

by the liver and spleen

Where are RBCs produced after birth

red bone marrow

Blood cell production in children

bones are filled with red bone marrow

Blood cell production as a person matures

fatty yellow bone marrow incapable of erythropoiesis gradually replaces red marrow

which places do red bone marrow remain even after maturaity

the sternum, ribs, pelvis, and upper ends of the limb bones

how is Erythropoiesis controlled by erythropoietin

1. kidneys detect reduced O2- carrying capacity of blood

2. when less O2 is delivered to the kidneys, they secrete erythropoietin into blood

3. Erythropoietin stimulates erythropoiesis by red bone marrow

4. additional circulating erythrocytes increase O2- carrying capacity of blood

5. increases O2- carrying capacity relieves initial stimulus that triggered erythropoietin secretion

agglutination

clumping of red blood cells in response to a reaction between an antibody and an antigen

antigens

a chemical that stimulates cells to produce antibodies

antibodies

a protein that reacts against a specific target

ABO Blood Types

inherited antigens

Type A blood

contains A antigens and B antibodies

Type B blood

contains B antigens and A antibodies

Type AB blood

contains both A and B antigens and no antibodies

Type O blood

do not contain A or blood and both A and B antibodies

Rh blood group was named after

rhesus

Rh postive

presence of antigens D or other Rh antigens on the red blood cell membranes